As is known, a control rod comprises:                a slender body which has a longitudinal axis,        a first fixing head, positioned at a first end of the body, comprising a first through-hole which has a first axis secant to the longitudinal axis, and        a second fixing head, positioned at a second end of the body, comprising a second through-hole which has a second axis secant to the longitudinal axis.        
Functionally, a control rod makes it possible to link two elements by maintaining a constant distance and ensuring the transmission of the forces between the two linked elements.
Hereinafter in the description, the length of the control rod corresponds to the center distance, separating the first and second axes, measured on the longitudinal axis.
According to an embodiment, to obtain a length-adjustable control rod, the body comprises a first part, which has a tapped barrel, and a second part, which has a threaded rod comprising a single continuous thread in the form of a helix configured to be screwed into the tapped barrel of the first part. Thus, it is possible to modify the length of the control rod by screwing the first and second parts relative to one another to a greater or lesser extent. A lock-nut is provided to immobilize the first and second parts in the set position.
According to this embodiment, it is not possible to modify the length of the control rod without modifying the orientation of one of the first and second axes of the through-holes.